Adds the ability to sync just one conversation

kordophoned/src/daemon/signals.rs

@@ -1,4 +1,10 @@
 #[derive(Debug, Clone)]
 pub enum Signal {
+    /// Emitted when the list of conversations is updated.
     ConversationsUpdated,
+
+    /// Emitted when the list of messages for a conversation is updated.
+    /// Parameters:
+    /// - conversation_id: The ID of the conversation that was updated.
+    MessagesUpdated(String),
 }